Table of Contents

• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

This dataset includes metrics related to coral energy reserves.  Fragments of coral species (Orbicella faveolata, Porites astreoides, and Porites divaricata) were analyzed for concentrations of lipids, proteins, carbohydrates, and chlorophyll a. Carbon isotopic ratios d13C and d15N were measured in both the host and endosymbiont.  Health metrics are included which describe bleaching status.

These data were published in:

Schoepf V, Grottoli AG, Levas SJ, Aschaffenburg MD, Baumann J, Matsui Y, Warner ME. (2015) Annual coral bleaching can impair the long-term recovery capacity of corals. Proceedings of the Royal Society B 282: 20151887. http://dx.doi.org/10.1098/rspb.2015.1887.  

Experimental Design (text extracted from Grottoli et al., 2014.  See publication for figures and full methods description)

In July 2009, 10 coral fragments from nine healthy colonies of Porites divaricata (branching morphology), Porites astreoides (mounding/encrusting morphology), and Orbicella faveolata (formerly Montastraea faveolata (large, mounding morphology) were collected near Puerto Morelos, Mexico (20 deg 500 N, 86 deg 520 W region).  Parent colonies were all at least 10m apart and thus assumed to be genotypically different.  Fragments were mounted on labeled PVC tiles, and randomly placed in 10 shaded (600 umol photons m(-2)  s(-1) ) outdoor flow-through seawater tanks, allowed to acclimate for 5 days, and then buoyantly weighed. The temperature in five tanks was gradually raised to 31.5C +- 0.20C (single bleaching treatment) over 7 days then maintained at the elevated temperature, while the other five tanks received ambient reef water (controls; 30.6 C  +- 0.24C) . After 15 days, one treatment and one control fragment from each parent colony of each species were buoyantly weighed and then frozen at 80 C (0 weeks on the reef). The remaining fragments were transplanted back to the reef at 4.9 m depth (20 deg 52.8150 N, 86 deg 50.9890 W). After 6 weeks on the reef, one additional treatment and control fragment from each colony of each species were collected, buoyantly weighed, and frozen at 80C, while the remaining fragments stayed on the reef for a full year at ambient reef temperatures. 

Chlorophyll a was determined according to Jeffrey & Humphrey (1975)  and standardized to surface area (Marsh 1970). Chlorophyll a values at 0 and 1.5 months on the reef following repeat bleaching are from Schoepf et al. (2011).

Total soluble lipids, animal soluble protein and animal soluble carbohydrate were determined on ground, frozen coral fragments using established methods (Rodrigues & Grottoli 2007; Schoepf et al 2013) and then converted to Joules per gram ash-free dry weight (Gnaiger & Bitterlich 1984)).

Net calcification was determined using the buoyant weight technique (Jokiel et al 1978) and standardized to surface area. Calcification rates at 0 and 1.5 months on the reef following repeat bleaching are from Grottoli et al. (2014).

Tissue C and N isotopic analyses were performed on separated animal host and endosymbiont fractions using established methods (Rodrigues & Grottoli 2006; Hughes et al 2010).  The difference between d13Ch and d13Ce (i.e. d13Ch2e) was calculated to determine the relative contribution of photoautotrophic versus heterotrophic carbon to the coral (Rodrigues & Grottoli 2006; Muscatine et al 1989). Repeated measurements of commercial standards (USGS-24, IAEA-N2) had a standard deviation of +- 0.04(permille) for d13C (n = 55) and +-0.11(permille) for d15N (n = 51).

References:

Gnaiger, E., and G. Bitterlich. "Proximate biochemical composition and caloric content calculated from elemental CHN analysis: a stoichiometric concept." Oecologia 62.3 (1984): 289-298. http://dx.doi.org/10.1007/BF00384259

Grottoli, Andréa G., et al. "The cumulative impact of annual coral bleaching can turn some coral species winners into losers." Global change biology 20.12 (2014): 3823-3833. http://dx.doi.org/10.1111/gcb.12658

Hughes, A. D., et al. "Acquisition and assimilation of carbon in non-bleached and bleached corals." Marine ecology progress series 420 (2010): 91-101. http://dx.doi.org/10.3354/meps08866

Jeffrey, SW T., and G. F. Humphrey. "New spectrophotometric equations for determining chlorophylls a, b, c1 and c2 in higher plants, algae and natural phytoplankton." Biochem Physiol Pflanz BPP (1975).

Jokiel, P. L., J. E. Maragos, and L. Franzisket. "Coral growth: buoyant weight technique." Coral reefs: research methods. UNESCO, Paris (1978): 529-541.

Marsh, James A. "Primary Productivity of Reef‐Building Calcareous Red Algae." Ecology 51.2 (1970): 255-263. http://dx.doi.org/10.2307/1933661

Muscatine, L., L. R. McCloskey, and R. E. Marian. "Estimating the daily contribution of carbon from zooxanthellae to coral animal respiration." Oceanography 26.4 (1981). http://dx.doi.org/10.4319/lo.1981.26.4.0601

Rodrigues, Lisa J., and Andréa G. Grottoli. "Calcification rate and the stable carbon, oxygen, and nitrogen isotopes in the skeleton, host tissue, and zooxanthellae of bleached and recovering Hawaiian corals." Geochimica et Cosmochimica Acta 70.11 (2006): 2781-2789. http://dx.doi.org/10.1016/j.gca.2006.02.014

Rodrigues, Lisa J., and Andréa G. Grottoli. "Energy reserves and metabolism as indicators of coral recovery from bleaching." Limnology and oceanography52.5 (2007): 1874-1882. http://doi:10.4319/lo.2007.52.5.1874

Schoepf, Verena, et al. "Short-term coral bleaching is not recorded by skeletal boron isotopes." PloS one 9.11 (2014): e112011. http://dx.doi.org/10.1371/journal.pone.0112011

Schoepf, V., et al. others (2013) "Coral energy reserves and calcification in a high-CO2 world at two temperatures." PLoS ONE 8: e75049. http://dx.doi.org/75010.71371/journal.pone.0075049

Details of the statistical analysis methods are in Schoepf et al 2015.

BCO-DMO Processing Notes:

• added conventional header with dataset name, PI name, version date
• modified parameter names to conform with BCO-DMO naming conventions
• replaced blanks with underscores
• added lat and lon of sampling locations based on coordinates in Grottoli et al. 2014. 

(Extracted from the NSF award abstract)

The overall stability and health of coral reefs is declining world-wide at an unprecedented rate. Mass coral bleaching, wherein exposure to elevated temperature leads to the loss of significant numbers of endosymbiotic dinoflagellates (Symbiodinium spp., commonly called zooxanthellae) and/or photosynthetic pigments, serves as a primary global example of how fragile this symbiosis is. While we have begun to understand the ecological and physiological impacts of bleaching, there remain key fundamental gaps in knowledge. In particular, it is becoming increasingly clear that a) not all corals either respond to, or recover from, bleaching events the same way, and that b) the impact of annual or repeated bleaching events on corals has not been examined in sufficient detail. Several non-mutually exclusive ecological and physiological pathways could impact how a particular coral species succumbs to or recovers from bleaching. Recent evidence suggests that the following features may play key roles for coral survival in the face of future seawater warming and mass bleaching events: 1) shifts in trophic partitioning (e.g., proportional reliance on autotrophy and heterotrophy) and energy reserve utilization, 2) enhanced thermal tolerance through host and algal-mediated physiological responses, and 3) harboring of different Symbiodinium phylotypes. However, these mechanisms have yet to be investigated in a unified approach that covers the entire coral holobiont system (algae, host tissue, and skeleton), or under scenarios of repeated bleaching.

The overall objectives of this study are as follows: 1) to determine the effect of single and repeated bleaching on the physiology, biogeochemistry, and recovery of some Caribbean coral species, and 2) to determine which Symbiodinium-type and host-species combinations are more resilient to single and repeated bleaching, what aspects of their physiology and biogeochemistry render them resilient, and to use this information to evaluate the long-term persistence of Caribbean coral reefs. To address these objectives, the following physiological variables will be measured: 1) Symbiodinium type, photochemical function and algal stress physiology, and 2) animal host energy reserves, defense enzyme concentration, skeletal growth, and feeding capacity in the corals Porites porites, Porites astreoides, and Montastraea faveolata. Corals will be examined immediately following thermal stress designed to approximate natural bleaching, and recovery will be monitored over short and long-term time scales. Next, the impact of repeated bleaching will be examined in the subsequent year, followed by examination over the next recovery period. This research is designed to simultaneously evaluate the symbiotic algae, coral host, and skeleton, and to identify patterns of physiological responses and recovery of each Symbiodinium-type and host-species combination that would be indicative of the resilience capacity of Caribbean corals to future more frequent thermal perturbations.